Windows 2008 R2 DFS doesn’t seem to use all the bandwidth available

If you have just created a DFS replication between 2 machines, it should start replicating. However you will notice that the replication is extremely slow and usually does not take up too much of the available bandwidth, epecially in an intranet environment.

What happens is in Windows Server 2008 R2, by default DFS replication turns on remote differential compression (rdc). What RDC does is to just send delta changes from the source to destination servers.

This works great if you

1. are paying for bandwidth
2. have a low bandwidth pipe to do the transfer
3. have large files
4. Have ample CPU, Ram, Disk

 

But its crap when

1. there are lots of small files
2. the link is a strong pipe (e.g intranet environment)
3. Don’t have so much CPU, Ram, Disk or those can be better utilized (delta changes takes up cycles and space)

 

So what you can do, if you do not want to enable RDC?

1. Start up DFS management
2. Select the replication that you want to modify
3. Click on the connections tab
4. Select the connections in questions (multiple selection is possible)
5. Right click, properties
6. Uncheck “Use remote differential compression (RDC)”
7. Click ok

And the next thing you know, DFS will start gobbling up your bandwidth to send all the files over asap!